function datatype, value
;+
; function returns the datatype of value
;-
compile_opt hidden
array = size(value)

type = array[n_elements(array)-2]
case type of
  0: type = 'undefined'
  1: type = 'byte'
  2: type = 'integer'
  3: type = 'long'
  4: type = 'float'
  5: type = 'double'
  6: type = 'complex'
  7: type = 'string'
  8: type = 'structure'
  9: type = 'DoubleComplex'
  10: type = 'pointer'
  11: type = 'object'
  12: type = 'unsigned integer'
  13: type = 'unsigned longword integer'
  14: type = '64-bit integer'
  15: type = 'unsigned 64-bit integer'
endcase
return,type
end